The patent literature discloses a plasma generator as an element analyzer. The plasma generator is a device in which air bubbles are generated in a channel that includes a narrow portion, plasma is generated in the air bubbles, and the resulting light emission is measured. In patent literature 1, plasma in the narrow portion of the channel is measured, and in patent literature 2, plasma in a region other than the narrow portion is measured. However, in each of the described devices, there is a problem because the retention of generated air bubbles in the narrow portion of the channel exerts an influence on the intensity of the plasma light emission, which results in low reproducibility of the plasma light emission.
In order to solve this problem, patent literature 3 discloses a method for avoiding the retention of air bubbles by removing the air bubbles through moving a solution in the channel. However, there is a problem in that a discharge unit such as a syringe pump is required in order to move the solution, with the result that the size of the plasma generator is increased.